The grades of three life science stocks are better this week, according to the Portfolio Grader database. Every one of these stocks has an “A” (“strong buy”) or “B” overall (“buy”) rating.

This week, Quintiles Transnational Holdings, Inc. (Q) is making solid headway. The company’s rating improves to an A (“strong buy”) from last week’s B (“buy”) rating. In Portfolio Grader’s specific subcategories of Earnings Growth and Margin Growth, Q also gets A’s. Shares of the stock have been changing hands at an unusually rapid pace, three times the rate of the week prior. For more information, get Portfolio Grader’s complete analysis of Q stock.

The rating of Covance (CVD) moves up this week, rising from a B to an A. Covance is a drug development services company providing a range of early-stage and late-stage product development services to the pharmaceutical, biotechnology, and medical device industries. Shares of the stock have been changing hands at an unusually rapid pace, twice the rate of the week prior. For more information, get Portfolio Grader’s complete analysis of CVD stock.

Albany Molecular Research, Inc. (AMRI) is bettering its rating of C (“hold”) from last week to a B (“buy”) this week. Albany Molecular Research provides contract services to various pharmaceutical and biotechnology companies primarily in the United States, Europe, and Asia. For more information, get Portfolio Grader’s complete analysis of AMRI stock.

Louis Navellier’s proprietary Portfolio Grader stock ranking system assesses roughly 5,000 companies every week based on a number of fundamental and quantitative measures. Stocks are given a letter grade based on their results — with A being “strong buy,” and F being “strong sell.” Explore the tool here.